Perfluoroalkanesulfinates are compounds that are useful, for example, as intermediates of medicine and agricultural chemical raw materials. Patent Publication 1 describes potassium trifluoromethanesulfinate as an intermediate of sulfonyl compounds, which are said to be useful for diabetes, etc. Furthermore, Patent Publication 2 discloses that a perfluoroalkanesulfinate is useful as a perfluoroalkylation agent.
As a conventional method for producing perfluoroalkanesulfinic acid derivatives, there is disclosed in Patent Publication 3 a method for producing a fluoroalkanesulfinic acid by reacting a perfluoroalkanesulfonyl fluoride with hydrazine into a hydrazium salt, and then reacting it with an acid.
Furthermore, Patent Publication 4 discloses a method for producing an alkali metal salt of perfluoroalkanesulfinic acid by bringing a perfluoroalkanesulfonyl fluoride into contact with an alkali metal sulfite in the presence of water. Non-patent Publication 1 discloses a method for obtaining potassium trifluoromethanesulfinate by reacting trifluoromethanesulfonic chloride with potassium sulfite. Non-patent Publication 2 discloses a method of reacting sodium carbonate or potassium carbonate with trifluoromethanesulfinic acid, thereby obtaining a corresponding sulfinate.
Furthermore, Non-patent Publication 3 also discloses that a zinc salt of tifluoromethanesulfinic acid is formed by reacting trifluoromethanesulfonyl chloride with zinc powder.
Furthermore, Non-patent Publication 4 discloses a method for obtaining potassium trifluoromethanesulfinate by reacting benzyl trifluoromethyl sulfone, potassium carbonate, and ethyl 3-bromopropionate.
Furthermore, Patent Publication 5 discloses a method in which hydrazine is reacted on a perfluoroalkanesulfonyl halide to obtain a perfluoroalkanesulfinic acid hydrazine salt (RfSO2H.N2H4), followed by a conversion into a perfluoroalkanesulfinate.